The professional bodybuilder-turned-actor shocked users on website Reddit after he commented on a thread with people arguing over exercise techniques on an entry titled 'Best Damn Cardio Humanly Possible in 15 Minutes'.

He wrote: ''Everybody, behave and stop bickering. This is about inspiring more people to get into fitness.

''I've never understood people who argue constantly about who is wrong and who is right in fitness, because the fact is, there are many 'right' answers, especially for people just starting out.''

The 'Last Stand' star encouraged hopefuls to discover their own fitness regime while remaining open-minded with regards to the training styles of other athletes.

He added: ''Do you think Sergio Oliva and I did the same thing? No. In fact, you could walk into Gold's and watch the 5 best guys and see 5 completely different routines. And you know what? We didn't argue.

''Do me a favour. Try to focus more on expanding the fitness community as a whole than protecting your little corner of it.''

It was recently revealed Arnold would be appearing in 'Terminator 5', the latest installment in his iconic franchise, and he admitted his pride at returning as the title character.

He previously said: ''I'm very happy that the studios want me to be in 'Terminator 5' and to star as the Terminator, which we start shooting in January. I feel very proud of that. I feel very happy and I'm looking forward to [it].''